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Abstract:

The present invention provides a railroad vehicle having a truck
structure in which soundproof effect can sufficiently be enhanced.
Soundproof member 22 having flexibility is mounted to support member 21
fixed to axle box 15. The support member is fixed to the axle box at an
outer side of a vehicle body at wheel 14 in such a manner that the lower
end thereof is located above a position set beforehand. The soundproof
member is arranged parallel to the rail at the outer side of the vehicle
body at the position where the wheel rolls on rail 17. The upper part of
the soundproof member is mounted to the support member in such a manner
that the position thereof in the vertical direction can be adjusted, and
the lower end of the soundproof member is located above a surface of the
rail.

Claims:

1. A railroad vehicle including a truck in which both ends of an axle
respectively mounted to a wheel are supported by an axle box so as to be
capable of rotating, the railroad vehicle comprising: a metallic support
member fixed to the axle box; and a soundproof member having flexibility
and is mounted to the support member, wherein the support member is
mounted at an outer side of the vehicle body at the wheel such that an
upper part thereof is fixed to the axle box in a state in which a lower
end thereof is located above a position set beforehand, and the
soundproof member is arranged in a direction parallel to a rail at the
outer side of the vehicle body at a position where the wheel rolls on the
rail, wherein the upper part of the soundproof member is attached to the
support member, while the lower end of the soundproof member is located
above a surface of the rail.

2. The railroad vehicle according to claim 1, wherein the soundproof
member is attached to the support member in such a manner that a position
in a vertical direction can be adjusted.

3. The railroad vehicle according to claim 1, wherein an upper part of
the support member is fixed to a bottom surface of the axle box.

4. The railroad vehicle according to claim 2, wherein an upper part of
the support member is fixed to a bottom surface of the axle box.

5. The railroad vehicle according to claim 1, wherein the upper part of
the support member is fixed to an outer surface of the lower part of the
axle box.

6. The railroad vehicle according to claim 2, wherein the upper part of
the support member is fixed to an outer surface of the lower part of the
axle box.

7. The railroad vehicle according to claim 1, wherein the upper part of
the support member is fixed to an outer surface of an axle support
portion of the axle box.

8. The railroad vehicle according to claim 2, wherein the upper part of
the support member is fixed to an outer surface of an axle support
portion of the axle box.

9. The railroad vehicle according to claim 1, wherein the upper part of
the support member is fixed to an inner surface of the axle support
portion of the axle box.

10. The railroad vehicle according to claim 2, wherein the upper part of
the support member is fixed to an inner surface of the axle support
portion of the axle box.

Description:

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a railroad vehicle, and more
particularly to a railroad vehicle having mounted thereto a truck having
a sound insulating structure in order to suppress diffusion of rolling
noise of wheels.

[0003] 2. Description of the Related Art

[0004] In a railroad vehicle running at high speed, a soundproof cover is
provided to suppress diffusion of operation noise from an underfloor
equipment that causes noise, for environmental consideration. There has
been known a truck for a railroad vehicle in which, in order to suppress
diffusion of rolling noise of a wheel, a noise absorbing material along a
longitudinal direction of a rail is fixed to an axle box body at a
position near a position where the wheel is in contact with the rail and
at a position apart from the side face of the wheel by the width of the
rail toward the width direction of the truck (e.g., see Patent Document
1).

[0005] In the truck for the railroad vehicle, the noise absorbing material
is attached to a mounting bearing, which is made of an iron metal plate
and is mounted to the axle box body, at the side of the rail. When the
running railroad vehicle is derailed, the rail is held in between the
wheels and the noise absorbing material (mounting receiver) so as to
attain a guide function by the rail.

[0007] However, in the structure described in Patent Document 1, the
position of the lower end of the mounting receiver is restricted to a
position higher than a rolling stock gauge or other set limits, since the
mounting receiver mounted to the axle box body is made of a metal.
Therefore, the position of the noise absorbing material is higher than
the position where the wheel is in contact with the rail, resulting in
that the rolling noise from the lower part of the noise absorbing
material is diffused in the ambient environment. Accordingly, a
sufficient sound absorbing effect cannot be obtained.

SUMMARY OF THE INVENTION

Problems to be Solved by the Invention

[0008] In view of this, an object of the present invention is to provide a
railroad vehicle having a truck structure in which a soundproof member,
which absorbs a rolling nose of a wheel or reflects the rolling noise in
the direction toward the inside of the vehicle body, can be made close to
the position where the wheel is in contact with the rail, and the
soundproof effect can sufficiently be enhanced.

Means for Solving the Problems

[0009] In order to attain the foregoing object, the railroad vehicle
according to the present invention includes a truck in which both ends of
an axle respectively mounted to a wheel are supported by an axle box so
as to be capable of rotating, the railroad vehicle including: a metallic
support member fixed to the axle box; and a soundproof member having
flexibility and is mounted to the support member, wherein the support
member is mounted at the outer side of the vehicle body at the wheel such
that the upper part thereof is fixed to the axle box in a state in which
the lower end thereof is located above a position set beforehand, and the
soundproof member is arranged in the direction parallel to a rail at the
outer side of the vehicle body at the position where the wheel rolls on
the rail, wherein the upper part of the soundproof member is attached to
the support member, while the lower end of the soundproof member is
located above a surface of the rail.

[0010] The soundproof member in the railroad vehicle according to the
present invention is mounted to the support member in such a manner that
the position thereof in the vertical direction can be adjusted. The upper
part of the support member is fixed to any one of the bottom surface of
the axle box, the outer surface at the lower part of the axle box, the
outer surface of the axle support portion of the axle box, and the inner
surface of the axle support portion of the axle box.

Effect of The Invention

[0011] According to the railroad vehicle of the present invention, the
soundproof member has flexibility, whereby the soundproof member can be
arranged at the position lower than a rolling stock gauge or other set
limits. Therefore, the position of the soundproof member can be made
close to the position where the wheel is in contact with the rail.
Accordingly, the soundproof effect by the soundproof member can be
enhanced. Since the soundproof member is attached such that the position
in the vertical direction can be adjusted, the present invention can
easily be adapted to the change in the height due to the wheel turning.
The holding member can be fixed to any selected one of the bottom surface
of the axle box, the outer surface of the axle box, the outer surface of
the axle support portion of the axle box, and the inner surface of the
axle support portion of the axle box, according to the structure of the
axle box and relation to the other devices mounted to the axle box.
Therefore, the support member can be adapted to various types of the axle
box.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] FIG. 1 is a front view of a truck of a railroad vehicle according
to a first embodiment of the present invention.

[0013] FIG. 2 is a front view of the essential part of the truck
illustrated in FIG. 1.

[0014] FIG. 3 is a side view of the essential part of the truck
illustrated in FIG. 1.

[0015]FIG. 4 is a front view illustrating an essential part of a truck of
a railroad vehicle according to a second embodiment of the present
invention.

[0016] FIG. 5 is a side view of the essential part of the truck
illustrated in FIG. 5.

[0017] FIG. 6 is a front view illustrating an essential part of a truck of
a railroad vehicle according to a third embodiment of the present
invention.

[0018]FIG. 7 is a side view of the essential part of the truck
illustrated in FIG. 6.

[0019] FIG. 8 is a front view illustrating an essential part of a truck of
a railroad vehicle according to a fourth embodiment of the present
invention.

[0020] FIG. 9 is a side view of the essential part of the truck
illustrated in FIG. 8.

[0021] FIG. 10 is a sectional view taken along a line X-X in FIG. 9.

[0022] FIG. 11 is a front view illustrating an essential part of a truck
of a railroad vehicle according to a fifth embodiment of the present
invention.

[0023] FIG. 12 is a side view illustrating a part of a cross-section of
the essential part of the truck illustrated in FIG. 11.

[0024] FIG. 13 is a front view illustrating an essential part of a truck
of a railroad vehicle according to a sixth embodiment of the present
invention.

[0025]FIG. 14 is a side view illustrating a part of a cross-section of
the essential part of the truck illustrated in FIG. 13.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0026] In a first embodiment of the present invention illustrated in FIGS.
1 to 3, a truck 10 of a railroad vehicle according to the present
embodiment includes a truck frame 12 that elastically supports a vehicle
body through an air spring 11, and a pair of front and rear wheel sets 14
held at the front and the rear of the truck frame 12 via a corresponding
axle box suspension 13. The axle box suspension 13 is a so-called wing
type. A wing portion 15a is projected at the front and the rear of an
axle box 15 that holds both ends of an axle 14a of the wheel set 14, and
a pair of axle springs 16 made of a coil spring is disposed between the
wing portion 15a and the truck frame 12. A soundproof member 22 having
flexibility is provided at the bottom surface of the axle box 15 through
a metallic support member 21.

[0027] The support member 21 in the present embodiment has a fixed plate
portion 21a that is fixed to the bottom surface of the axle box 15 with
fixing bolts 23, plural support arms 21b mounted at the bottom surface of
the fixed plate portion 21a in the direction of a sleeper, and a mounting
plate portion 21c mounted at the outer end of the support arms 21b. The
mounting plate portion 21c is made of a metallic material, and is
arranged such that the plate surface directs toward the rail direction
and vertical direction at the outer side of the vehicle body at the wheel
14b of the wheel set 14. The mounting plate portion 21c is formed with a
plurality of bolt insertion holes 24, which are elongated holes in the
vertical direction, for mounting the soundproof member. The shape and
size of the support member 21 are set such that the lowermost end of the
support member 21, i.e., the lower edge of the mounting plate portion 21c
in the present embodiment, is located above a position set beforehand,
e.g., a position that is set as a lower limit value of an unsprung
device, specifically, a position above a rail surface by 60 to 70 mm.

[0028] The soundproof member 22 is a plate-like member arranged, in a
direction parallel to the rail, at the outer side of the vehicle body at
the position where the wheel 14b rolls on the rail 17. Not only it has
flexibility, but also it can absorb a rolling noise generated when the
wheel 14b rolls on the rail 17. The soundproof member 22 is also made of
a material which has strength capable of enduring aerodynamic air flow
and is excellent in weather resistance. For example, urethane foam,
semihard rubber, or rubber used for an automobile tire can be used
singly, or these materials can appropriately be combined, as the
material.

[0029] The soundproof member 22 is mounted in such a manner that the
lowermost end thereof is located above the top surface of the rail 17,
e.g., above the rail surface by 10 to 30 mm, in order that the soundproof
member 22 is not brought into contact with the rail 17 or a railroad
crossing, when the railroad vehicle runs at the place where the rails 17
cross each other at a turnout or through a railroad crossing.

[0030] Plural mounting through-holes 25 corresponding to the bolt
insertion holes 24 of the support member 21 are formed at the upper end
of the soundproof member 22. The soundproof member 22 is attached to the
support member 21 by mounting bolts 26 and mounting nuts 27 inserted
respectively through the bolt insertion holes 24 and the mounting
through-holes 25. When the position of inserting the mounting bolt 26
into the bolt insertion hole 24 is changed, the mounting height of the
soundproof member 22, i.e., the position of the lowermost end of the
soundproof member 22 can be adjusted. With this adjustability, even when
the diameter of the wheel 14b is decreased due to the wheel turning, the
position of the lowermost end of the soundproof member 22 can easily be
adjusted to the set position.

[0031] Since the plate-like soundproof member 22 having flexibility is
provided in the direction parallel to the rail 17 at the outer side of
the vehicle body at the position where the wheel 14b rolls on the rail
17, the diffusion of the rolling noise of the wheel 14b in the ambient
environment can be prevented. In particular, the soundproof member 22 is
arranged below the support member 21 that is fixed to the axle box 15
moving in the vertical direction together with the wheel 14b, and the
lower end of the metallic support member 21 is lowered to the position
set beforehand. Further, the soundproof member 22 having flexibility is
provided so as to be suspended at the bottom part of the support member
21. Therefore, the soundproof member 22 can surely be held and can be
lowered to the position close to the rail 17, whereby the soundproof
effect by the soundproof member 22 can be enhanced.

[0032] FIGS. 4 and 5 illustrate a second embodiment of the present
invention. In the description below, the components same as those in the
first embodiment are identified by the same numerals, and the detailed
description will not be repeated here.

[0033] The second embodiment illustrates the case in which an upper part
of a plate-like support member 31 is fixed to the lower part of an outer
surface of the axle box 15 with fixing bolts 32, and the soundproof
member 22 same as that in the first embodiment is attached at the lower
part of the support member 31. In this embodiment, plural bolt insertion
holes 24, which are elongated holes in the vertical direction as in the
first embodiment, are formed at the lower part of the support member 31.
The soundproof member 22 is attached to the support member 31 by the
mounting bolts 26 and the mounting nuts 27 inserted respectively into the
bolt insertion holes 24 and mounting through-holes 25, in such a manner
that the vertical position thereof can be adjusted.

[0034] FIGS. 6 and 7 illustrate a third embodiment of the present
invention. In this embodiment, an upper part of a support member 41 is
fixed to the outer surface of an axle support portion 15b of the axle box
15. The axle support portion 15b is formed to have a cylindrical shape so
as to enclose the end of the axle 14a. An annular fixing portion 41a
corresponding to the outer periphery of the end face of the cylindrical
axle support portion 15b is provided at the upper part of the support
member 41, while a mounting plate portion 41b, which is arranged such
that the plate surface directs toward the rail direction and the vertical
direction, is provided at the lower part of the support member 41, as in
the above-mentioned respective embodiments. Plural bolt insertion holes
24, which are elongated holes in the vertical direction, are formed at
the lower part of the mounting plate portion 41b, as in the
above-mentioned embodiments.

[0035] In this embodiment, the fixing portion 41a of the support member 41
is fixed to the outer surface of the axle support portion 15b by the
plural fixing bolts 42, and the soundproof member 22 is attached to the
lower part of the support member 41 by the mounting bolts 26 and the
mounting nuts 27 inserted respectively into the bolt insertion holes 24
formed on the mounting plate portion 41b and mounting through-holes 25
formed on the upper part of the soundproof member 22, in such a manner
that the vertical position thereof can be adjusted.

[0036] FIGS. 8 to 10 illustrate a fourth embodiment of the present
invention. In this embodiment, an upper part of a support member 51 is
fixed to the inner surface of the axle support portion 15b of the axle
box 15. An annular fixing member 51b having an axle insertion hole 51a,
which has an inner diameter by which the axle 14a can be inserted, is
provided at the upper part of the support member 51. The fixing portion
51b is fixed to the inner surface of the axle support portion 15b by
plural fixing bolts 52, in a state in which the axle 14a held by the axle
support portion 15b is inserted into the axle insertion hole 51a.

[0037] As in the above-mentioned respective embodiments, a mounting plate
portion 51c is mounted at the lower part of the support member 51 in such
a manner that the plate surface directs toward the rail direction and
vertical direction. Plural bolt insertion holes 24, which are elongated
holes in the vertical direction, are formed on the mounting plate portion
51c. In this embodiment, the soundproof member 22 is attached to the
support member 51 by the mounting bolts 26 and the mounting nuts 27
inserted respectively into the bolt insertion holes 24 formed at the
lower part of the support member 51 and mounting through-holes 25 formed
on the upper part of the soundproof member 22, in such a manner that the
vertical position thereof can be adjusted.

[0038] FIGS. 11 and 12 illustrate a fifth embodiment of the present
invention. In this embodiment, a support member 61 is inserted, instead
of an adjusting plate inserted between the top surface of the wing
portion 15a and the lower end of the axle spring 16. Specifically, the
L-shaped support member 61 is used, which includes a pair of horizontal
fixing portions 61a having a cutout formed at the middle portion in the
rail direction corresponding to the axle support portion 15b, and a
mounting plate portion 61b extending in the rail direction and bending
downward in the vertical direction from one side edge of the fixing
portion 61a. The fixing portion 61a is inserted and fixed between the top
surface of the wing portion 15a and the lower end of the axle spring 16.
The soundproof member 22 is mounted at the lower part of the support
member 61 by the mounting bolts 26 and the mounting nuts 27 that are
inserted through the bolt insertion holes 24 and the mounting
through-holes 25 formed on the mounting plate portion 61b extending
downward from the outer end of the fixing portion 61a, in such a manner
that the vertical position thereof can be adjusted.

[0039] FIGS. 13 and 14 illustrate a sixth embodiment of the present
invention. In this embodiment, the inserting direction of the support
member 61 illustrated in the fifth embodiment is made reverse to that in
the fifth embodiment. Specifically, in the fifth embodiment, the support
member 61 is arranged such that the mounting plate portion 61b is located
at the outside of the axle box 15. On the other hand, in the present
embodiment, the support member 61 is arranged such that the mounting
plate portion 61b is located at the inside of the axle box 15, wherein
the soundproof member 22 mounted to the mounting plate portion 61b so as
to be capable of being adjusted in the vertical direction and the wheels
14a are made closer to each other than those of the fifth embodiment.

[0040] As described above, the shape of the support member supporting the
soundproof member 22 is selected according to the structure and shape of
the axle box in the truck of the railroad vehicle. Therefore, the present
invention is applicable not only to a truck in which a lower part of an
axle box is relatively large, such as a truck having a wing-type axle box
suspension, but also to a truck in which an axle box is relatively small,
such as a truck having a monolink-type or an axle-arm-type axle box
suspension. The present invention is also applicable to a truck including
a speed detector or a brake disk arranged at the outside of the axle box
by appropriately selecting the mounting position of the support member.